Lubricant



Patented Apr. 6, 1943 LUBRICANT Clarence M. Loane, Hammond, Ind., JamesW. Gaynor, Chicago, 111., and Lawson W. Mixon. Hammond, Ind., assignorsto Standard Oil Company, Chicago, 111., a corporation of Indiana NoDrawing. Application March 24, 1941,

' Serial No. 384,942

8 Claims. (01. 252-48) The present invention relates to improvementsinadditives for mineral oils and in particular to an improved phosphoruscontaining additive for mineral oils and to the method ofpreparing thesame.

In copending applications, Serial No. 384,940, filed March 24, 1941, andSerial No. 384,941, filed March 24, 1941, there are respectivelydescribed as additives to mineral oils phosphorus sulfidehydrocarbonreaction products and neutralized phosphorus sulfide-hydrocarbonreaction products which are effective in inhibiting the deterioration ofmineral oils and the attendant formation of sludge, carbon andvarnish-like deposits and the method of preparing the additive.

While the phosphorus sulfide-hydrocarbon reaction products as describedin the aforesaid copending applications are very effective in inhibitingthe deterioration of mineral oils and in preventing the formation ofsludge, carbon and/or varnish-like deposits in internal combustionengines during use, they possess a characteristic odor which may beconsidered objectionable by users of oils containing such additives.

It is an object of the present invention to provide a method ofimprovingthe odor ofphos phorus sulfide-hydrocarbon reaction productswithout decreasing the effectiveness of the reaction products. It is afurther object of the invention to provide a substantially odorlessphosphorus sulfide-hydrocarbon reaction product which is effective ininhibiting the deterioration of mineral oils and which is effective in,preventing the formation of sludge, carbon and/or varnish-like depositsin internal combustion engines during use; I

We have discovered that the foregoing objects can be attained byreacting the phosphorus sulfide-hydrocarbonreaction product or theneutralized reaction product with an agent having an active hydrogenatom at elevated temperatures, for example, from about 200 F'. to about600 F., and preferably from about 300 F. to about 400 F.,eitherundiluted or in solution in oil or other suitable solvents.Illustrative of the type of agents having an active hydrogen atom atelevated temperatures which are .well suited for the hereindes cribedpurpose are steam, alcohols, ammonia and amines.

The phosphorus sulfide used in the'preparation of the additive can beany phosphorus sulfide, such as, for example, P2Sa, P285, P451, P433,etc. and preferably, P285.

I The hydrocarbon reactants can be paraffins, olefins, or olefinpolymers, aromatics, or alkyl aromatics, cyclic aliphatics, petroleumfractions such as lubricating oil fractions, petrolatums, waxes, crackedcycle stocks, condensation products of petroleum fractions, solventextracts of petroleum fractions, etc.

The paraflln hydrocarbons can be those ob,-

tained from petroleum oils such as bright stock residuums, lubricatingoil distillates, petrolatums, or parafiin waxes. We may also halogenateany of the foregoing parafl'ins and condense the same with aromatichydrocarbons in the presence of anhydrous inorganic halides, such asaluminum chloride, zinc chloride, boron fluoride and the like.

As examples of high molecular weight olefinic hydrocarbons which we mayemploy as reactants are cetene, (C16), cerotene (C26) melene (C30) andmixed high molecular weight alkenes obtained by cracking petroleum oils.I

As starting materials for the production of olefin polymers, we canemploy the individual olefins themselves, mixtures of olefins, ormixtures of olefins and non-olefinic compounds. 'For example, theolefin-i0 starting material can be butylenes, amylenes, refinery gasescontaining normally gaseous olefins and cracked distillates or otherrelatively low-boiling hydrocarbon mixtures containing normally liquidolefins and mixtures of normally liquid olefins containing substantialamounts of dissolved normally gaseous olefins. We may also employolefinsobtained by the cracking of paraflin wax or by the dehalogenationof alkyl halides, particularly long chain alkyl halides.

The polymers referred to above may be those obtained by polymerizingolefinic hydrocarbons in the presence of catalysts such as sulfuricacid. phosphoric acid, aluminum chloride, zinc chloride, boron fluorideand other catalysts of the Friedel-Crafts type. For example, we canemploy the polymers resulting from the treatment of mono-olefins,preferably iso-mono-olefins such as isobutylene and isoamylene, and/orthe, co-

polymers obtained by the polymerization of hydrocarbon mixturescontaining low molecular weight iso-olefins and normal olefins,preferably those of less than six carbon atoms.

We can also employ as the starting material the-polymer or syntheticlubricating oil obtained by polymerizing unsaturated hydrocarbonsresulting from the vapor phase cracking of paraffin waxes in thepresence of aluminum chloride. This is fully described in United StatesPatents 1,995,260, 1,970,002 and 2,091,398. Still another type of olefinpolymer which can be employed is in a non-oxidizing atmosphere.

the polymer resulting from the treatment of vapor phase cracked gasolineand/or, gasoline fractions with sulfuric acid or solid absorbents suchas fullers earth whereby unsaturated polymerized hydrocarbons areremoved. We may also employ'as a starting material the polymersresulting from the voltolization of hydrocarbons as described, forexample, in United States Patents 2,197,768 and 2,191,787.

Another class of compounds which maybe used as starting materials is thearomatic hydro carbons such as for example benzene, naphthalene,toluene, xylene, diphenyl and the like, or

alkylated aromatic hydrocarbons such as, for example, an alkylsubstituted benzene in which the alkylradical has at least four carbonatoms and preferably at least eight carbon atoms such as a long chainparaffin wax.

The phosphorus sulfide-hydrocarbon reaction product may be obtainedbyreacting a phos-' phorus sulfide, for example, P285, with any of theabove described hydrocarbons at temperatures of from about 200 F. toabout 500 F. and preferably from about 300 F. to about 400 F. andpreferably in a non-oxidizing atmosphere, such as an atmosphere ofnitrogen. From about 1.0% to product as above obtained, normally shows atitratable acidity which is neutralized when the reaction product istreated with a basic reagent.

The phosphorus sulfide-hydrocarbon reaction product when neutralizedwitha basic reagent having a metal constituent is characterized by thepresence or retention of the metal -con stituent of the reagent. Othermetal constituents, such as heavy metal constituentsjmay be introducedinto the neutralization product by reacting the same with a salt of thedesired heavy metal.

The term "neutralized phosphorus sulfide-hydrocarbon reaction product"vasused herein means a phosphorus sulfide-hydrocarbon reaction prodnothaving at least about 1% of its titratable acidity reduced by thereaction with a basic reagent and includes the neutralized phosphorussulfide-hydrocarbon reaction products containing a metal constituentresulting from said neutraliz ation or resulting from the reaction of aheavy metal salt'with the phosphorus sulfide-hydrocarbon reactionproduct treated witha basic reagent.

The phosphorus sulfide-hydrocarbon reaction product may be neutralizedby treating the reaction product with a suitable basic compound such asa hydroxide, a carbonatejor an oxide of an alkaline earth metal or analkali metal, preferably calcium oxide, potassium hydroxide, or sodiumhydroxide. Other basic reagents may be-used such as, for example,ammonia or an metal constituent such as, for example, tin, titanium,aluminum, chromium, cobalt, iron and the like, may be obtained byreacting a salt of the desired heavy metal with the phosphorussulfide-hydrocarbon reaction products which have been treated wtih abasic reagent. When the neutralization is accomplished with a polyvalentbasic metal, such as lime, a product having excess basicity may beobtained.

Both the phosphorus sulfide-hydrocarbon reaction product and theneutralized reaction product, particularly ifthe latter is incompletelyneutralized, possess a characteristic odor which they impart to thelubricant to which they are added. While this does not in any way impairthe effectiveness of the compounds in inhibiting the formation of sludgeand varnish, it may be objectionable from a sales viewpoint. Theseproducts can be substantially freedof this odor by reacting the samewith a compound having an active hydrogen atom at an elevatedtemperature, for example, from about 100 F. to 600 F. and preferablyfrom about 300 F. to 400 F. until a substantial portion of the sulfur isremoved as hydrogen sulfide, and the product is substanti'ally odorless.While we may employ compounds such as alcohols, ammonia, and/or amineswe prefer to employ steam. lhus, the aforesaid reaction products can bereadily freed of the odor by blowing steam through the reaction productseither in an undiluted state or in solution in oil or other suitablesolvent while maintaining the mixture at the aforesaid temperatures.

Treating the phosphorus sulfide-hydrocarbon reaction products with acompound having an active hydrogen atom, such as steam, at an elevatedtemperature, results in the final product containing substantiallysmaller amounts of sulfur. This, however, has substantially no effect onthe sludge and varnish inhibiting properties of the product.

The method of preparing the phosphorus sulride-hydrocarbon reactionproduct and the method of subsequently deodorizing the same will beillustrated by the following specific examples, which are given merelyby way of illustration and not'intended 'to limit the scope of thepresent invention.

EXAMPLE I A mineral lubricating oil derived from a socalled Winklercrude oil, and having a gravity of 25.6 A. P. I., a Saybolt Universalviscosity at 100 F. of 285 to 300 seconds, a flash of not less than 400F. anda pour point of 5 F. was

alkyl or aryl substituted ammonia, 'such as.

amines. The neutralization may be carried out As aforesaid when thephosphorus sulfide-hydrocarbon reaction product is neutralized with abasic compound having a metal constituent the neutralized reactionproduct is characterized by the presence of the metal constituent of thebasic reagent. Neutralized reaction products containing a heavy mixedwith 9% of phosphorus pentasulfide and the mixture heated at atemperature of from F. to 400 F. for about three hours and maintained atthe maximum temperature for an additional hour. The reaction product wasthen diluted with 50% of an SAE 20 motor oil and blown with steam at atemperature of 340-350 F. for about three hours. The final product wasubstantially freeof any odor.

EXAMPLE II temperature range for three more hours, and the product wasblown with steam within this same as the product in Example IV.

2,316,083 v temperature i 'ange for t hree more hours. The

fi'nafp'mduct containing phosphorus and potassium, was substantiallyodor-free.-

EXAMPLE III A cracked cycle stock,"recovered as bottoms from a bubbletower, andhaving a Saybolt Universal viscosity at 100. E. of 53 seconds,a gravity of 23.2 A. P. 1., an initial boiling point of 408 F., and a90% distillation point of 734 F., was mixed with 9% or phosphoruspentasuifide and the mixture heated at a'temperature of from about300-400 I". The mixture was then dissolved in hexane, filtered, and thefiltrate distilled to remove the hexane.- The product was then dilutedwith 50% of an SAE 20 motor oil and blown with steam at a temperature of340- 380" F. untilsubstantially no hydrocarbon sulilde was evolved. Thisproduct was substantially odor-free.

An. isobutyi'ene 'polymer havingafiaybolt Universal'viscosity at 210 F.of about 3000 seconds was'heated with 10% of phosphorus pentasulfide ata temperature or about 380 F. for eight hours. The, "reaction product soobtained was cooled, 3% of KOH 'was'added, and the mixture was heated at180 F. for two hours. end of the two hour period the temperature wasraised to about 340-350 F. and'maintained within this temperature rangefor three hours. This product had a characteristic odor and showed the"following analysis:v

I Percent j; Phosphorus 3.0? Sulfur 3.97 Potassium 2.1

The aboveproduct was diluted with an equal volume or an SAE 20'motor oiland steam blown for" three andone-hali hours at temperatures of fromabout (MO-350 F. At the end of this period the product wassubstantiallyfree of any characteristic odor, end showed approximately the samephosphorus and potassium content but showed substantially no sulfur.

- EXAMPLE V The olefin polymer-used in Example IV was treated with 1.0%phosphorus pentasulilde at a temperature oi 380. F. for eight hours. Thephosphoruspentasulflde-olefln polymer reaction product was then. dilutedwith an equal volume of an SAE20 motor oil and treated with 3% oipo-.tassium hydroxide at a temperature of 180 -F. for two hours. At the endof thetwo hours heating period the temperature was raised to 340-381) F.and the product was steam blown within this temperature range for threehours. The final product was substantially free. of sulfur and thecharacteristic odor, andcontained substantially thessm'e amount ofphosphorus and potassium At the not substantially free of thecharacteristic odor was obtained.

The effectiveness of the deodorized phosphorus sulfide-hydrocarbonreaction products in improving the stability of lubricating oils maybedemonstrated by a test described as follows: Two hundred and fifty cc.of the oil to be tested is heated at 330 F. to 332 F. in a 500 cc. glassbeaker in the presence of five square inches of copper and ten squareinches of iron. Four glass rods of six millimeter diameter are suspendedin the oil which is stirred at about 1300 R. P. M. with a glass stirrerhaving a 40 blade pitch. At stated intervals oil samples are taken andthe sludge, acidity and viscosity values determined. The glass rods arealso inspected for evidence of varnish formation thereon. Varnish valuesare based on a visual rating in which glass rods free of any varnisharegiven a rating of 10, heavily coated rods are given a rating of 1, androds having coatings between these extremes are given intermediatevalues between 1 and 10.

The following oils were subjected to the above test:

Oil A-Control (high grade SAE 20 motor oil).

Oil BOil A+1% of the deodorized product of Example IV. l

Oil C-+Oil A+1% of the deodorized product of Example V.

i Saybolt Universal viscosity at F.

l 10=no deposit; 1 =very heavy deposit.

The above data show the marked improvement obtained by the addition ofsmall amounts of the deodorized phosphorus sulfide-hydrocarbon reactionproduct to a high grade SAE 20 motor oil.

The effectiveness of the deodorized phosphorus sulfide-hydrocarbonreaction products in inhibiting the formation of carbon, sludge and/orvarnish in internal combustion engines is demonstrated by the followingdata obtained in an engine 'test conducted in a standard six cylinderspark-ignition engine operating for sixty hours at 35 B H. P. and 3000R. P. M. and an oil sump temperature of about 285 F. At the end of eachtest period the engine was dismantled-and given a visual engine ratingin which a rating of 10 means that the engine parts had substantiallythe same appearance at the end of the test as at the start of the test,while an engine rating or 1 means that the engine parts are very badlycoated. An engine rating of intermediate value between 1 and 10 meansthat the appearance of the engine parts after the test is between theseextremes. In the tabulation below the visual ratings are given on thefollowing oils.

Oil A-Control (high grade SAE 20 motor oil). Oil B-Oil A+%% deodorizedreaction product of Example VI. Oil C-Oii A+%% deodorized reactionproduct of Example VI. v Oil D-Oil A+1% deodorized reaction product oiExample V.

TABLE II Aconnmwrnp Enema Tns'r Visual engine ratings at end of 60 hoursOil samples A B O 1) Piston varnish 5 6 10 i Sludge deposits-... 6 8 910 Ring belt carbon 0 l0 l0 Under crown carbon 5 10 Overall rating--- 5.3 7. 2 9. l5 10 'While we may use the deodorized phosphorus.

sulfide hydrocarbon reaction products in lubrieating oils, which may beused in such oils in amounts of from about 0.001% to 10.0% andpreferably from about 0.01% to about 3.0%, our invention is not limitedto such use, since these products may be used in other petroleumproducts, such as insulating oils, white oils, greases,

' waxes, etc. to inhibit the oxidation, sludging and deteriorationthereof.

Although we have described preferred embodiments of our invention, othermodifications may be made without departing from the scope and spirit ofthe invention, and we do not wish to limit our invention to the specificexamples set forth herein, except insofar as the same is defined by thefollowing claims.

We claim:

1. A lubricant comprising a mineral lubricating oil'anda small amount oftheproduct obtained by reacting a phosphorus sulfide with a hydrocarbon,neutralizing the reaction productlresult ing therefrom with abasicreagent whereby a neutralized phosphorus "and sulfur-containing reactionproduct is obtained, and subsequently blowing the neutralized phosphorussulfide-hy- -drocarbon reaction product with steam at a temperature offrom about 200 F, to about 600 F. to obtain a substantially sulfur-freeproduct.

2. A lubricant as described in claim 1 in which the hydrocarbon is apetroleum oil fraction.

3. The method of inhibiting the formation of sludge, carbon and varnishin an internal combustion engine lubricated with a mineral lubricatingoil comprising lubricating the internal combustion engine with alubricant comprising a mineral lubricating oil normally susceptible toform sludge; carbon and varnish during use in an internal combustionengine, and a small amount of the product obtained by reacting a,phosphorus sulfide with a hydrocarbon, neutralizing the resultingreaction product with a basic reagent whereby a neutralized phosphorusand sulfurcontaining product is obtained and subsequently treating theneutralized reaction product with a compound having an active hydrogenatom at an elevated temperature above about F. to obtain a final producthaving a substantially lower sulfur content than the initial neutralizedreaction product.

4. The method of inhibiting the formation of sludge, carbon andvarnish=in an internal combustion engine lubricated with a mineral lubrieating oil, comprising lubricating the internal combustion engine witha, lubricant comprising a mineral lubricating oil normally susceptibleto form sludge, carbon and varnish during use in an internal combustionengine, and a small amount of the product obtained by reacting a.phosphorus sulfid with a hydrocarbon, neutralizing the resultingreaction product with a basic reagent whereby a neutralized productcontaining phosphorus and sulfur is obtained and subsequently blowingthe neutralized reaction product with steam at an elevated temperatureabove about 200 F. to obtain a substantially sulfur-free product.

5. A lubricant comprisinga hydrocarbon lubricating oil and a smallamount of the product obtained by reacting'a phosphorus sulfide with ahydrocarbon, neutralizing with a'b'asic reagent whereby a neutralizedproduct containing phosphorus and sulfur is obtained, and subsequentlytreating said reaction product"at'a temperature above about 100 F. withacompound having an active hydrogen atom to obtain a; product having asubstantially lower sulfur'content' than the initial reaction product.

- 6. A new composition comprising a hydrocarbon oil and the productobtained by the process comprising reacting a phosphorus sulfide with ahydrocarbon, whereby a product containing phosphorus and sulfur isobtained, neutralizing with a basic reagent and treating the reactionproduct at a temperature above about 100 F. with a compound having anactive hydrogen atomto'obtain a final product having a substantiallylower sulfur content than the initial reaction product. f-

7. A new composition comprising a hydrocarbon oiland the productobtained by reacting a phosphorus sulfide with a hydrocarbon,neutralizing the reaction productresulting therefrom' with a basicreagent having a metal constituent whereby a phosphorus andsulfur-containing product having a, metal constituent is obtained andsubsequently blowing the neutralized reaction product with steam atatemperature above about 200 F. to obtain a substantially sulfur-freeproduct. g

8. A new composition comprising a. hydrocarbon oil and the productobtained by the process comprising reacting a phosphorus sulfide with ahydrocarbon whereby a phosphorus and sulfurcontaining product isobtained-neutralizing with a basic reagent having a metal constituent,and treating the reaction product at a temperature above about 100. F.with a compound having an active hydrogen atom to obtain a substantiallysulfur-free product.

CLARENCE M. LOANE. JAMES W. GAYNOR. LAWSON W. MIXON.

